A clustering algorithm based on link availability for MANET

The cluster topology management in the MANET network is studied in. The classic Lin-Gerla clustering algorithm is improved to increase the logical topological stability. By considering the node mobility in the communication systems, the notion of relative motion is introduced, and the nodes more stable are chosen as the cluster-heads, which effectively increases the stability of mobile network with Random Direction Model. Regarding the possible high concentration, a fast cluster splitting method is proposed for cluster maintenance. The simulation and performance analysis for the improved algorithm are given.     

一种基于距离和角度的无线传感器网络GPSR协议

传感器节点能量是影响无线传感器网络的生存周期的关键因素,基本的GPSR协议所使用的贪婪算法忽略了角度因素对下一跳选择的影响,在转发失败遇到空洞问题时只能进行周边边界转发算法,以损耗节点能量为代价。为了节约节点能量,延长网络生存周期,从改进GPSR协议出发,综合考虑距离和角度这两个因素解决路由过程中的空洞问题。仿真实验表明,改进后的协议是网络节点消耗大大减少,网络生存时间为300 s,长于基本GPSR协议下的200 s。该协议缩短了路径长度,节约节点能量,减少能量的消耗,延长了网络生存时间。     

A fuzzy logic multicasting algorithm for ad hoc networks

To increase the multicasting efficiency of Ad hoc networks, a fuzzy logic multicasting algorithm (FLMA) is proposed. FLMA adopts the fuzzy logic to tolerate the imprecise information caused by dynamic network topology. The two input variables of the fuzzy logic system are the relative degree of the additional coverage node number and the relative degree of the residual energy. The deferring time of rebroadcast is the output variable of the fuzzy logic system, which is used to optimize the priority of the nodes to rebroadcast. FLMA reduces the redundant retransmission and the chance of the contention and collision, while balances the energy consumption of the nodes. Simulation results reveal that the FLMA achieves better performance than BCAST in terms of the network lifetime, average end-to-end delay, the average number of drops per node and the throughput.     

Analysis of a New Distributed-Pump Scheme Applied in District Heating Network

It is helpful for energy efftciency to use distributed pumps instead of valves to regulate hydraulic balance in a district heating system (DHS). A new scheme of distributed pump-system is presented based on performance comparison of hydraulic regime and power saving of single-heat-source dendritic pipeline networks with regulating valves and/or distributed pumps. Supposing that the new scheme was employed in multi-sources looped-pipe network, theoretical analysis and case study were carried out to evaluate off-design performances including hydraulic self-regulation, supply water temperature stability and power-saving potential. The results indicated that the proposed scheme would contribute to minimizing power consumption, retarding water temperature change, and would be convenient to adjust the quality and quantity independently in the looped-pipe heat supply networks.     

Distribution of trust model in P2P network based on equilibrium theory

There are a large number of malicious attack nodes and collusion groups in P2P(peer to peer) network, and the existing trust models improve the P2P network environment to some extent, but the emphasis of the models are different, which are unable to fully solve large-scale malicious attacks and deception. Therefore, a P2P trust model based on equilibrium theory is presented. The model consists of the construction of the trust structure, the malicious node detection and trust speculation. It constructs trust network according to the equilibrium theory, uses the equilibrium theory to define nodes balance factor, detects balance malicious nodes by calculating the impact of malicious behavior on the network, and adopts trust inference algorithm to estimate trust nodes to prevent distrust network nodes being added. Experimental results show that the model is reliable, and the algorithm is efficient and robust.     

Intrusion Detection Based on Adaptive Immune Classifier

The distribution properties of the normally data and anomaly data in the network connectivity features have huge differences ; therefore, there exist the low rate of detection and false positive rate problem for the traditional classifier which is applied to the network intrusion detection. An adaptive classifier based on the artificial immune cluster is presented. The new classifier adopts multi -granularities idea and it effectively eliminates the inconsistency between the classification algorithm and the clustering algorithm. Through the classification of the data sets in real variety of network intrusion data sets, experimental results show that the classifier has high detection rate and low false positive rate; it has better classification performance and generalization ability than RBF and BP classifiers.     

On-demand routing algorithm based on load balancing and mobility prediction in wireless mobile Ad hoc network

The traditional routing protocol for wireless mobile ad hoc networks is unable to achieve balanced energy consumption and could not adapt to the dynamic topology changes well.A novel on-demand rooting algorithm is proposed based on load balancing and mobility prediction.The proposed rooting algorithm excludes the unstable links in routing discovery,and allows the node with more energy forward the routing request packet preferentially.In addition,it adopts the active local routing recovery strategy by predicting the link connection time,and finishes the repair work before the link being actually failure.The simulation experiments demonstrate that,comparing with the traditional AODV protocol,with slight increase of the rooting control overhead,the proposed algorithm increases the average packet delivery ratio,decreases the average end-to-end delay of the data packets,and achieves load balancing in the network and prolong the life-span of the network,which shows the proposed algorithm is highly practical.     

Optimal sensor deployment scheme for heterogeneous wireless sensor networks

For the high density of distributed heterogeneity nodes in wireless sensor networks (WSNs), the optimal sensor deployment is studied. A cost optimal heterogeneous sensor deployment scheme based on genetic algorithm is proposed. The cost of sensor node deployment is used as objective function for optimization computation subjected to network coverage and fault tolerance to obtain the suitable types and positions of the sensors. The algorithm can be used for boolean sensing model as well as probabilistic sensing model. The simulation results demonstrate that the proposed algorithm converges fast toward the optimal solutions and reduces the cost of sensor deployment, which is feasible for heterogenous nodes deployment in WSNs.     

AN APPROACH TO SHARE DISTRIBUTED RESOURCES IN A LOCAL AREA NETWORK

An algorithm of sharing distributed resoumes in a local area network is proposed , which is based on Queuing theory and statistics of probability. It is proved by means of a emulative program that this algorithm is simple, feasible and applicable.     

Feed-forward Neural Network Based onGaussNewton-NL2SOL Algorithm and Its Application

Though the feed forward neural network based on GaussNewton algorithm and its derivation will converge with order two, it is only effective toward little residual problem. In order to solve the little and large residual problems at the same time, NL2SOL algorithm is introduced and combined with the GaussNewton algorithm so as to form a feed forward neural network based on GaussNewton-NL2SOL algorithm. The application shows that this neural network can solve the residual problem properly and the convergence and stability of it performs well.     

An Unicast Fault-tolerant Routing Algorithm on Locally Twisted Cubes

The locally twisted cube is a newly topological structure of network. The authors we design a unicast fault-tolerant routing algorithm on the locally twisted cube by utilizing safety levels and the feature of the network. The performance of the proposed algorithm is evaluated through simulation experiments. When the number of faulty nodes reaches or exceeds half of the total, it can still achieve a quite high percentage of successful routing. An additional advantage of the routing algorithm is that it is highly probable that the selected route be a shortest route between the associated nodes.     

移动Ad Hoc网络AODV路由协议的研究与优化

无线移动自组网是仅由移动节点所组成的网络,具有分布式控制、自组织、多跳等特点,由于该网络具有抗毁性能高、易铺设等性质,越来越受到业界的广泛关注。原始的路由协议已经满足不了现有网络不可预测、频繁变化的拓扑结构的需要,因此,在之前研究的基础上,对现有Ad Hoc网络AODV路由协议进行了研究,并设计出一种基于AODV协议的改进路由协议——基于认知的AODV协议(Cognitive-based AODV,CAODV)。通过NS2进行试验仿真,结果表明,CAODV协议具有比AODV协议更加优良的性质,可以有效降低重启路由发现频率,增加断裂链路的修复成功率,降低协议的控制负载,对现有网络的动态变化具有很强的适应能力。     

An improved localization algorithm based on RSSI for landslide monitoring

In order to overcome the existing problems of low automation, high cost and difficult to implement in the area of landslide monitoring, this paper presents a new method of RSSI (Received Signal Strength Indicator)based positioning technology without any one-off instruments to monitor landslide surface displacement. By adding weighted factors, the improved positioning algorithm can estimate the parameters of the path loss model dynamically and calculates the communication distance of network nodes in real-time, which can improve positioning precision and reduce the impact of environmental changes on it. The MATLAB experiments show that, compared with the traditional RSSI based localization algorithm using fixed pass loss model, the improved algorithm could significantly reduce the average error.     

大型商场建筑夏季冷负荷动态预测模型

夏季建筑冷负荷的正确预测是实现大型复杂中央空调优化运行、节能降耗的关键。笔者探讨了商场建筑冷负荷的主要影响因素,确定了建筑动态冷负荷预测模型的输入,提出了夏季基于新风机组供电频率的商场顾客率间接测量方法,解决了商场内顾客量难以检测的难题。还提出了AFC-HCMAC神经网络预测模型算法,实现了大型商场建筑冷负荷的动态预测。仿真结果表明:顾客率在商场冷负荷预测中占有重要地位,在冷负荷预测模型中增加商场顾客率可显著提高预测精度;AFC-HCMAC神经网络预测算法与传统的HCMAC神经网络算法比较,可有效降低神经网络节点数,提高预测精度。     

Application of improved genetic algorithm to locating and sizing of distributed generation

A Prüfer-coded genetic algorithm based on the decimal number of nodes is proposed and it is used to solve collaborative optimization planning of access solution of distributed generation(DG)and structure of distribution network.Using graph theory to generate theoretically feasible topology structureand the access nodes and the installed capacity of distributed generation are coded by the Prüfer number.The coding method makes the distribution network operation structure and the access solution of DG combine into the evolution problem of the same chromosomal gene.The length of the chromosome coding of this method is shorter than binary encoding.This solution takes full advantage of the Prüfer-coded to improve computational efficiency and convergence rateand makes some restrictions and improvements in some key parts of the algorithm to solve the problem illegal solution.Finallyfeasibility and superiority of the algorithm is validated by a case study.     

对北京地区小麦高产育种的看法

分析北京地区冬小麦高产育种的进展及问题,提出高产品种模式以中间型模式较现实可行,设计时应注意:1.对产量构成三因素要统筹兼顾,尽量挖潜,争取综合优势.2.协调穗粒数与抗寒及熟期的矛盾,在中等小穗数的基础上争取提高小穗结实数并力争减少不孕小穗数.3.穗粒重构成的三种类型,穗粒数/千粒重是:(1)中上/中上,稳产性好,较易实现;(2)中上/上,高产潜力大;(3)上/中,利于协调高产与优质.4.兼具中上等分蘖力,越冬抗寒性好及成穗率高,可获较高的亩穗数.5.株高80—85厘米,收获系数0.44—0.50为宜.多穗与大粒结合型,也可获得高产.     

Improvement and performances of DV hop localization algorithm in wireless sensor networks

In order to improve the node localization precision of Range Free based DV Hop localization algorithm in wireless sensor networks (WSNs) with randomly distributed nodes and dynamic topology, the improved algorithm is proposed. After analyzing the DV Hop algorithm, considering the obvious errors of the estimated node coordinates calculated by Polygon based method in traditional DV Hop algorithm, the numerical iterative algorithm is constructed by employing Taylor series expansion, and simulation studies for the improved DV Hop algorithm are conducted. The selection criteria for the convergent threshold of iterative step is determined, the localization performance of the improved localization algorithm is analyzed by comparing with the traditional DV Hop algorithm under the same condition of selected convergent threshold and simulation parameters, while the calculation amount and convergence rate of the improved algorithm are also measured by the statistic iterations. The simulation results show that by selecting reasonable iterative threshold values and appropriately increasing calculation amount for node localization, the improved DV Hop localization algorithm greatly improves the localization precision and the error stability, which is feasible for node localization in WSNs with both randomly distributed nodes and dynamic topology.     

SEEIP核心企业局域智慧能源网络框架及优化配置方法

智慧节能工业园区（SEEIP）的核心企业能源配置对产业集群的循环经济节能降耗具有重要作用。针对SEEIP建设与既有工业园区核心企业能源系统的智慧化改造,提出一种基于信息和通信技术（ICT）的局域智慧能源网络框架,并给出了能源生产模块、能源转换模块与能源蓄存模块中各种能源介质及品位的能量计算数学模型。以经济成本与环境影响为目标的函数,给出了SEEIP企业能源网络系统配置的优化模型,并采用改进的差异演化算法（DE）结合数据库查询技术求解该混合整数非线性规划（MINLP）优化问题,给出企业能源系统最佳配置方案,以满足用户冷、热、电需求。     

基于复杂网络的民族地区农村居民点布局优化——以贵州省黎平县为例

民族地区的农村居民点因受国家政策及人类活动的影响而亟待转型,探索此区域农村居民点的布局优化模式有利于推进该区域国土空间治理和全面实现乡村振兴。以民族地区典型代表区贵州省黎平县为研究区,采用AHP法、GIS空间分析法、复杂网络、Python语言编程等方法集成分析研究区农村居民点的优化布局模式。结果表明：（1）研究区农村居民点综合影响力在22.30~76.09之间,中高等水平的农村居民点居多,农村居民点综合影响大小分布不均。（2）以农村居民点综合影响力为切入点构建农村居民点复杂网络,网络的联系性、集中性强但中心性一般。在空间上,网络节点分布不均且差异明显,中心性强的节点集聚分布。将复杂网络的5个指标加权求和后,依据分析结果将黎平县农村居民点优化布局模式归纳为集聚发展型、重点发展型、潜力优化型、规模控制型、迁村撤并型。     

Hierarchical self-localization of underwater wireless sensor network nodes

The follow-up application of underwater wireless sensor network is influenced by accuracy of self-localization of nodes. The self-localization of nodes is discussed in this paper. First of all, nodes of underwater wireless sensor network are classified into several levels according to the accuracy of position of nodes and the levels are from the first to the fifth in accordance with accuracy of nodes from high to low respectively. Secondly, the level of anchor nodes can be known by those unknown nodes from the information given by the anchor nodes themselves, At the same time the unknown nodes are able to be located in the area controlled by the first level of anchor nodes that are as the aggregation. Then the positioning algorithm is designed correspondingly in accordance with the accuracy level of nodes. Finally, the positioning algorithm is simulated and analyzed. The result shows that the unknown nodes can be located effectively by hierarchical control.